Tags

Type your tag names separated by a space and hit enter

Effects of short-term concentric vs. eccentric resistance training on single muscle fiber MHC distribution in humans.
Int J Sports Med. 2005 Jun; 26(5):339-43.IJ

Abstract

The purpose of this investigation was to determine the effects of a concentric vs. eccentric resistance training program on single muscle fiber myosin heavy chain (MHC) adaptations in humans. Fifteen sedentary, healthy males were divided into three groups: concentric training (CTG) (n = 6, 24.2 +/- 1.7 y, 181 +/- 2 cm, 82.5 +/- 4.6 kg), eccentric training (ETG) (n = 6, 23.7 +/- 1.6 y, 178 +/- 3 cm, 90.4 +/- 6.1 kg), and control (CTL) (n = 3, 23 +/- 1.5 y, 181 +/- 2 cm, 97 +/- 13.2 kg). The subjects performed 4 sets of 8 unilateral repetitions starting at 80 % of concentric 1-RM, 3 days/week for a total of 4 weeks. Subjects were tested pre- and post-training for concentric 1-RM. Muscle biopsies were obtained from the vastus lateralis pre- and post-training for determination of single fiber MHC isoform distribution using SDS-PAGE/silver staining (100 fibers analyzed/subject pre- and post-training). Fibers expressing more than one MHC isoform (i.e., hybrid fibers) were analyzed for relative MHC isoform proportions via densitometry. The training program resulted in a 19 % 1-RM strength gain for CTG (p < 0.05) with no change in ETG or CTL. MHC-IIx fibers decreased by 7 % in CTG (p < 0.05) and ETG had an 11 % increase in total hybrids (MHC-I/IIa + MHC-IIa/IIx) (p < 0.05). No other differences were noted in MHC distribution among the three groups. Densitometry analysis of hybrid fibers showed no change in relative MHC isoform proportions pre- to post-training for any group. These data suggest that the MHC distribution did not change dramatically as a result of 4 weeks of concentric vs. eccentric resistance training despite the increase in whole muscle strength from concentric muscle actions.

Authors+Show Affiliations

Human Performance Laboratory, Ball State University, Muncie, IN 47306, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Clinical Trial
Comparative Study
Controlled Clinical Trial
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

15895315

Citation

Raue, U, et al. "Effects of Short-term Concentric Vs. Eccentric Resistance Training On Single Muscle Fiber MHC Distribution in Humans." International Journal of Sports Medicine, vol. 26, no. 5, 2005, pp. 339-43.
Raue U, Terpstra B, Williamson DL, et al. Effects of short-term concentric vs. eccentric resistance training on single muscle fiber MHC distribution in humans. Int J Sports Med. 2005;26(5):339-43.
Raue, U., Terpstra, B., Williamson, D. L., Gallagher, P. M., & Trappe, S. W. (2005). Effects of short-term concentric vs. eccentric resistance training on single muscle fiber MHC distribution in humans. International Journal of Sports Medicine, 26(5), 339-43.
Raue U, et al. Effects of Short-term Concentric Vs. Eccentric Resistance Training On Single Muscle Fiber MHC Distribution in Humans. Int J Sports Med. 2005;26(5):339-43. PubMed PMID: 15895315.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effects of short-term concentric vs. eccentric resistance training on single muscle fiber MHC distribution in humans. AU - Raue,U, AU - Terpstra,B, AU - Williamson,D L, AU - Gallagher,P M, AU - Trappe,S W, PY - 2005/5/17/pubmed PY - 2005/10/6/medline PY - 2005/5/17/entrez SP - 339 EP - 43 JF - International journal of sports medicine JO - Int J Sports Med VL - 26 IS - 5 N2 - The purpose of this investigation was to determine the effects of a concentric vs. eccentric resistance training program on single muscle fiber myosin heavy chain (MHC) adaptations in humans. Fifteen sedentary, healthy males were divided into three groups: concentric training (CTG) (n = 6, 24.2 +/- 1.7 y, 181 +/- 2 cm, 82.5 +/- 4.6 kg), eccentric training (ETG) (n = 6, 23.7 +/- 1.6 y, 178 +/- 3 cm, 90.4 +/- 6.1 kg), and control (CTL) (n = 3, 23 +/- 1.5 y, 181 +/- 2 cm, 97 +/- 13.2 kg). The subjects performed 4 sets of 8 unilateral repetitions starting at 80 % of concentric 1-RM, 3 days/week for a total of 4 weeks. Subjects were tested pre- and post-training for concentric 1-RM. Muscle biopsies were obtained from the vastus lateralis pre- and post-training for determination of single fiber MHC isoform distribution using SDS-PAGE/silver staining (100 fibers analyzed/subject pre- and post-training). Fibers expressing more than one MHC isoform (i.e., hybrid fibers) were analyzed for relative MHC isoform proportions via densitometry. The training program resulted in a 19 % 1-RM strength gain for CTG (p < 0.05) with no change in ETG or CTL. MHC-IIx fibers decreased by 7 % in CTG (p < 0.05) and ETG had an 11 % increase in total hybrids (MHC-I/IIa + MHC-IIa/IIx) (p < 0.05). No other differences were noted in MHC distribution among the three groups. Densitometry analysis of hybrid fibers showed no change in relative MHC isoform proportions pre- to post-training for any group. These data suggest that the MHC distribution did not change dramatically as a result of 4 weeks of concentric vs. eccentric resistance training despite the increase in whole muscle strength from concentric muscle actions. SN - 0172-4622 UR - https://www.unboundmedicine.com/medline/citation/15895315/Effects_of_short_term_concentric_vs__eccentric_resistance_training_on_single_muscle_fiber_MHC_distribution_in_humans_ L2 - http://www.thieme-connect.com/DOI/DOI?10.1055/s-2004-821041 DB - PRIME DP - Unbound Medicine ER -